Pipe perforator



Aug. 27, I935. o, ,1, McCULLOUGH I 2,0l2,314

PIPE PERFORATOR Filed Dec. 20, 1952 IIVVZ/VTOH.

0775 J. fiCULLOL/G/K Patented Aug. 27, 1935 oFFi 2,012,314 PIPE PERFORATOR at, J. McCullough, Huntington Park, Calif. Application December 20, 1932, Serial No. 648,066 10 Claims. (01. s 1 1ss) This invention relates to a pipe perforator whereby apertures are formed in a pipe below the surface of the ground.

The prime object of my invention is to provide a hovel means for expanding and contracting the perforating blade by the reciprocal movement of the body of the tool.

Another object is to provide a novel means for stopping the downward movement of the body of the tool when the perforating blade has been entirely expanded. A further object is to provide a novel means for locking the bottom mandrel while the tool is being lowered into the hole, said locking means being readily releasable when it is desired to operate the tool.

Other objects, advantages. and features of in- Vention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing Figure 1 is a side elevation of my pipe perforator.

Figure 2 is a longitudinal sectional View of the same in the position assumed when the perforating blade is completely expanded.

Figure 3 is a sectional View taken on line 33 of Figure 2; I Figured is a fragmentary longitudinal sectional view of the body and mandrel illustrating the locking means.

Referring more particularly to the drawing, the numeral I indicates the body of the toolpreferably cylindrical in form and this body is formed with a longitudinally extending groove 2. A cutter head 3 is reciprocally mounted in the groove 2 and this head is guided inits movement by means of a pair of projecting pins 4-4 which extend into and accurately fit guide grooves 55 formed in the body' I.

The perforating blade 6 projectsfrom the head 3 and this blade is adapted to be swung outwardly to perforate the pipe or casing, as will be further described.

A pair of bearing surfaces 1'! on the bottom of the head 3 bear against the upwardly inclined cam ribs 88. As the body I is moved downwardly, the head 3 rotates and the blade Ii enters the casing by the action of the cam ribs 8. The surfaces l-l are eccentric to the pins 44, and their engagement with the ribs 88 will rotate the head 3 clockwise, when viewed in Fig. 2. When the body i is pulled upwardly, the blade 6 is retracted by the finger 9 which engages the retracting cam surface Ill, Thecan I!) is oppositely in" clined to the ribs 8 and it will be evident that the finger 9 will cause the head 3 to pivot counterclockwise, as viewed in Fig. 2, around the pins l and retract the blade 6 when said finger engage the cam surface I0.

When the blade 6 is fully expanded, it is desirable to inform the operator of that fact and for that purpose I have devised a slip III which is slidably mounted at the upper end of the groove 2 and is engaged by the head 3 at the upper liznit of said heads movement, i. e., the head will engage the lower surface of the slip and the last part of its movement will force the slip outwardly into engagement with the casing,'and thus the downward movement of the body I will be stopped. A spring I2 serves to return the slip to its retracted position. 1

A mandrel I3 is slidably mounted in the lower end of the body I and projects into the groove 2.

A plurality of easing engaging springs 86 are fixedly mounted on the mandrel i3 for the purpose of frictionally engaging the casing for purposes to be further stated.

When the toolis being lowered into the well, a key I5 is fitted into a notch It in the mandrel and said key engages the bottom surface of the body I. Thus it will be evident that the mandrel is held against upward movement. When the tool has reached the point where it is desired to perforate the casing, ths-body I is pulled upwardly. The springs I 4 frictionally engaging the casing will hold the mandrel I3 against upward movement and the coil spring 1! is compressed. A spring I8 in the notch I G will force the key outwardly and the perforating operation can now be started. The key i5 dropsout of the mandrel I3 into the well. I

The blade 6 is started into the casing by lowering the body I, the springs l4 holding the mandrel I3 against downward movement and consequently, the mandrel will move upwardly into the groove 2 as shown in Figure 2. The head 3 is thus en gaged by the mandrel and is pushed upwardly in the groove and at the same time the cam ribs 3 engage the surfaces ll to swing the blade E outwardly into engagement with the casing. The surfaces l-'I are spaced from the pipedi, and their engagement with the ribs 8-45 will exert a clockwise rotative force on the head 3, as the body continues to move downwardly. Once the blade is in engagement with the casing, further downward movement of the body will cause the blade to be forced thru the casing to perforate the same by the cam action previously described. When the body I is pulled upwardly, the blade 6 is retracted in the manner previously described.

The usual threaded pin is is formed on the top of the body i so that it can be coupled to a string of drill pipe, or the like.

Having described my invention, I claim:

1. A pipe perforator comprising a body, a cutter head reciprocally and pivotally mounted in said body, a perforating blade on said head, cam means on the body engageable by the head on the upward movement thereof relative to the body whereby the perforating blade is swung outwardly, and cam means engageable by the cutter head on downward movement thereof relative to the body whereby said perforating blade is swung inwardly, and means engageable with the cutter head on downward movement of the body whereby the cutter head is initially started in its movement relative tothe body, and slip means in the body engageable by said head adjacent the upper part of its movement whereby said body is held against further downward movement,

2. A pipe perforator comprising a body, a cutter head reciprocally mounted in said body, a perforating blade on said head, cam means on the body engagea-ble by the ,headon the upward movement thereof relative to the body whereby the perforating blade is swung outwardly, and cam means engageable by the cutter head on downward movement thereof relative to the body whereby said perforating blade is swung inwardly, and slip means in the body engageable by said head adjacent the upper part of its movement whereby said body is held against further downward movement, and means engageable with the cutter head on downward movement of the body whereby the cutter head is initially started in its movement relative to the body.- g

3; A pipe perforator comprising a body, a cutter head reciprocally mounted in said body, a perforating blade on said head, cam means engageable by the head on the upward movement thereof whereby the perforating blade is swung outwardly, cam means engageable by the cutter head on downward movement thereof whereby said perforating blade is swung inwardly, a mandrel slidably mounted in said body, spring means on the mandrel adapted to engage the pipe to be perforated, said mandrel engaging the cutter head when the body is moved downweirdly, thereby starting the cutter head on its upward movement, and slip means in the body e'rigageable by said head adjacent the upper part of its movement whereby said body is held against further downward movement.

4. A pipe perforator comprising a body, a cut- .ter head reciprocally mounted in said body, a

perforating blade on said head, cam means engageable by the head on the upward movement thereof whereby the perforating blade is swung outwardly, cam means engageable by the cutter head on downward movement thereof whereby said perforating blade is swung inwardly, a mandrel'slidably mounted in said body, spring means on the mandrel adapted to engage the pipe to beperforated, said mandrel engaging thecutter head when the body is moved downwardly, thereby starting the cutterhead on its upward moves merit, and slip means engageable by said head adjacent the upper part of its movement whereby said body is held against further downward movement.

5. A pipe pe'rforator comprising a body, said body having a longitudinal extending groove therein, a cutter head reciprocally "mounted in the groove, a pair of projecting pins on the head, said body having guide grooves formed in the sides of said first named grooves, said pins projecting into said last named grooves, a perforating blade on the head, a pair of inclined cam ribs in the body, said head engaging the cam ribs whereby the perforating blade is swung outwardly upon movement of the body relative to the head, a retracting cam, said head engaging the retracting cam on downward movement thereof whereby the perforating blade is retracted, and means engageable with the cutter head on downward movement of the body whereby the cutter head is initially started in its movement relative to theb'o'dy, and slip means in the body engageable by said head adjacent the upper part of its movement whereby said body is held against further downward movement.

6. A. pipe perforator comprising a body, said body having a longitudinal extending groove therein, a cutter head reciprocally mounted in the groove, a pair'of projecting pins on the head, said body having guide grooves formed in the sides of said first named grooves, said pins projecting into said last named grooves, a perforating blade on the head, a pair of inclined cam ribs in the body, said head engaging the cam ribs on downward movement of the body whereby the perforating blade is swung outwardly, a retracting cam, said head engaging the retracting cam on downward movement thereof, whereby the perforating blade is retracted, and slip means engageable by the head adjacent the upper end of its movement whereby the slip means is forced outwardly to hold the body against continued downward movement, and means engageable with the cutter head on downward movement of the body whereby the cutter head is initially started in its movement relative to the body.

7. A pipe perforator comprising a body, said body having a longitudinal extending groove therein, a cutter head reciprocally mounted in the groove, a pair of projecting pins on the head, said body having guide grooves formed in the sides of said first named grooves, said pins projecting into said last named grooves, a perforating blade on the head, a pair of inclined cam ribs in the body, said head engaging the cam ribs whereby the perforating blade is swung outward- 1y, a retracting cam, said head engaging the retracting cam on downward movement thereof, whereby the perforating blade is retracted, a mandrel slidably mounted in said body, spring fingers attached to said mandrel whereby the mandrel is restrained against free movement, said mandrel being adapted to engage the cutter head and move it upwardly on downward movement of the body, and slip means in the body engageable by said head adjacent the upper part of its movement whereby said body is held against further downward movement.

8. A pipe perforator comprising a body, said body having a longitudinal extending groove therein, a cutter head reciprocally mounted in the groove, a pair'of projecting pins on the head, said body having guide grooves formed in the sides of said first named grooves, said pins projecting into said last namedgrooves, a perforating blade on the head, a pair of inclined cam ribs in the body, said head engaging the cam ribs whereby the perforating blade is swung outwardly, a retracting cam, said head engaging the retracting cam on downward movement thereof, whereby the perforating blade is retracted, a mandrel slidably mounted in said body, spring fingers attached to said mandrel whereby the mandrel is restrained against free movement, said mandrel being adapted to engage the cutter head and move it upwardly on downward movement of the body, and slip means engageable by the head adjacent the upper end of its movement whereby the slip means is forced outwardly to hold the body against continued downward movement.

9. A pipe perforator comprising a body, said body having a longitudinal groove therein, a cutter head, pins on the cutter head, guide grooves in the body, said pins extending into the guide grooves, a perforating blade extending from the cutter head, cam ribs in the body, said cutter head engaging the cam ribs to swing the perforating blade outwardly on downward movement of the body, a finger on the cutter head, a retracting cam, said finger engaging the retracting cam on upward movement of the body whereby the perforating blade is swung inwardly, and means engageable with the cutter head on downward movement of the body whereby thecutter head is initially started in its movement relative to the body.

10. A pipe perforator comprising a body, said body having a longitudinal groove therein, a cutter head, pins on the cutter head, guide grooves in the body, said pins extending into the guide grooves, a perforating blade extending from the cutter head, cam ribs in the body, said cutter head engaging the cam ribs to swing the perforating blade outwardly on downward movement of the body, a finger on the cutter head, a retracting cam, said finger engaging the retracting cam on upward movement of the body whereby the perforating blade is swung inwardly, and slip means in the body engageable by the cutter head at the top of its movement whereby said slip means is forced outwardly and the further downward movement of the body is prevented, and means engageable with the cutter head on downward movement of the body whereby the cutter head is initially started in its movement relative to the body.

OTIS J. McCULLOUGH. 

